The narrative will focus on themes of religion; as the town Pastor will interpret the feathered dinosaurs as perversions of angels or demons, or even the snake.
The lush green jungle of the Cretaceous period will be compared to Eden.
As the desperation to survive gets worse, the author will question their faith.
The incoming meteor will be seen as salvation coming for the sinners left behind but ends up killing all of them.
Except, of course, the author.

So yeah. I'm aware this is a very silly idea, at least on the surface.
Please tell me what you think and how I can make it better.

Okay, first thing's first: research is going to be key on this. Not just with the dinosaurs, but Frontier life as well. Like, where in the west is this going to be? That's going to affect what kind of dinosaurs are found there— for instance, if it's further north, it's going to overlap the Hell Creek formation, which includes parts of Montana, the Dakotas, and Wyoming, and is home to a lot of iconic dinosaurs, like T.rex and Ankylosaurus, and keep in mind these weren't all cotemperaneous— T. Rex and Triceratops both co-existed, but T. Rex and Deinonychus actually were about 50 million years apart— the former existed from 68 to 65 MYA, while the latter existed from 115-108 MYA.

Now that the dinosaur pedantry is out of the way, let's talk the old west. A lot of materials in the old west just wouldn't survive unless fossilized— human bones and such buried in the ground would easily undergo fossilization, and maybe the coffins around them would even make petrified wood. But materials such as aluminum start to decay after about 500 years, and anything above ground is going to be dust. For the sake of narrative convenience, I'd suggest the town flood at least once, and that the lockbox for the journal have something weird done to it to keep its contents from rotting— say, the preacher-man blesses it, because if we're bringing religion in, we may as well go whole hog.

I've only recently started doing homework on dinosaurs in preparation for this skip and realized I was not likely gonna make it in time for the 4k contest, which this was originally intended for. Thank you so much for the Hell Creek Formation though, that's a really good idea and an excellent place to start.

And, uh, thanks for the blessing idea. The alternative was quite literally going to be 'everything is anomalously well preserved'. Embarrassing, I know.

One question; you're suggesting that the town floods while they're stuck in the past in order to allow for better conservation of materials?

Fossilization is a tricky beast. The reason the majority of fossils we have exist is because they were preserved in wet sediment— a river bed, or a mudslide, that kind of thing. This is also why we have some dinosaur fossils with things such as feather imprints preserved.

This process can preserve whole-body fossils, provided they're dried after they're encased. Then, it's pressure— a whole lot of pressure, tons and tons of rock pushing down over the course of millions of years. The pressure removes the hydrogen and oxygen from the remains, leaving behind the carbon that makes up the bones. This is called Carbonization.

The most common form of fossilization is permineralization— soft tissues decay, and then mineral-rich water seeps into the rock and crystalizes the hard tissue.

Some materials outright don't fossilize unless under very favorable conditions— the reason why we have Megalodon teeth out the wazoo and not a complete Megalodon is because they're a shark, and cartilage— the majority of what a shark is made up of— is very difficult to fossilize.

Then there's "Mold and Cast" fossils— basically, the thing inside rots way, leaving a mold for other minerals to fill. A lot of trilobite and other pre-Cambrian, Cambrian, and other aquatic fossils are mold and cast.

Water does help with the fossilization process, because sediment covers the remains more quickly, allowing for better fossilization. After that, weight and pressure take over.

Hopefully that helps. Also, 4K posting is gonna be open for a while after the first, so even if you can't get it in immediately, you'll probably be able to get it in.